Method of preserving



Patented Apr. 14,1942 y v UNITED STATES PATENT OFFICE I I azsmoz J METHOD or raasaavmo V Robert H. Bedford, New mi. N. Y., assign or to The Atlantic Coast Fisheries Company, New

a York, N. Y., a corporation of Maine ,No Drawing. Application July 7, 1938.

Serial No. 217,923

. 13 Claims, (Cl. 99-160) p o This invention relates to the proces of preservdifliculties of eflicient extraction of the viscera ing perishable tissues containing vitamimbearwhen they arrive atthe plant on shore. I o ing oils in such a manner that the tissues bear- None of the, aforementioned prior-wart proing the oils lend themselves to eflicientinethods cedures has, therefore, been fully efiicaciousin so of separation of the oil and the oil produced there- 5 preserving the viscera of fish for extended pefrom retains its vitamins as well as its wholeriods at sea that. the oil subsequently extracted someness and purity when extracted. This invenby efiicient methods ashore will be wholesome, tlon relates more particularly to the preservation .of light color and of good quality from the point of i the viscera of fish. including liver, intestines of view of taste, odor, freedom of fatty acids and and other organs of the fish which; contain vitavitamin potency. min-bearing oils, and also the product resulting It is, therefore, an object of this invention to therefrom. so preserve tissues containing vitamin-bearing Prior to thisinvention, it has been customary oil, and particularly viscera of fish, for extended in the case of cod livers to bring the livers into periods of time so that the oil subsequently export from very short trips or else to try out the tracted willbe wholesome, of light color and of oil at sea, both procedurescontemplating the exgood quality from the point of view of taste, odor, tractionof oil while the livers are strictly fresh. i vitamin potency and freedom of fatty acids. Codfish livers are exceedingly perishable and, if Another object of the invention is to provide the oilisnotextractedimmediatelyfrom the strictpreserved tissues. containing vitamin-bearing ly fresh livers, bacterial and enzyme action splits oils, particularlyviscera of fish, which are cathe glycerides in. the cod liver oil to fatty acids .pable of being kept for extended periods of time and glycerine, while the bacterial and other and ,which will yield an oil,.will be wholesome, enzyme action gives a darkening of color, developof light color and of good quality from the point ment of foul odors and taste, and deterioration of of view of taste, odor, vitamin potency and free vitaminpotency; In the caseof longer fishing 2 dom of fatty acids. 1 trips at sea, such as those in the halibut fish- Other objects of the invention will become aping, it is not practicable to return to port promptparent from the following description and aply because of the great distance of the fishing pended claims. 1 grounds from port, so that'advantagecannot be In viscera, I have found that the reaction of taken of short trips for avoiding decomposition. the medium has an important influence on the On the other hand, in the case of such fish as activity of enzymes. I have found generally that. the halibut, the oil is so intimately bound in celluwhen the range .of hydrogen ion concentration lar structure of the liver and other viscera that is between pH 1.5 to pH 9.0, there will be enzyrnic it cannot be readily extracted by simple means, activity. I i such as could be employed on the deck of fishing Certain chemical substancesmay beinjurious boats at. sea.) i to one enzyme or typeof micro-organism and yet In the prior art, attempt has been made to comparatively harmless to another. i i solve thisproblem by removing the viscera from In the instant invention, I treat the tissues theflsh aboard fishing vessels, packing them in containing vitamin-bearing Oi s so t t t metal cans, and chilling these metal cans in ice. 40 drogenfion concentration thereof is increased in k While this attempted method of preservation is excessof pH 9.0 and at the same time inhibit,

undoubtedly better than no preservation at all, i. e: kill or arrest, the action of all the enzymes it is still .far removed from an ideal preservative and bacteria which produce theundesired results. in that the mild degree of chilling merelyslows In accordancewith the principles of the indownthe rate of deteriorationbut does not ar stant inventionjtissues containing vitamin-bear rest it. a ing oils, such as fish viscera, are treated with cer- Another approach to the solution of this probtain substances, hereinafter more fully described, him in the prior art hasbeen the use of certain I whereby said fish viscera are preserved for exchemical preservatives, such as formaldehyde, ended periodsof time so thatenzymic activi y is sodium chloride and various other organic and nhibited. the-greater part of the microbial popuinorganic preservatives, which tend to toughen lation is killed andthe rate of growth of the surand harden the tissues. 'While undoubtedly vivorsggreatly reduced, the original vitamin A- chemical preservatives of this kind can, and do potency is maintained and rancidity inhibited. effectpreservation of a sort by toughening and i The substances contemplated by this invention, i hardening the tissues, they tend to increase the and above referred to, are alkalis which have the give satisfactory results.

effect of producing such a high concentration of hydroxyl ions (in excess of pH 9.0) which tend to suppress enzyme action and at the same time kill or inactivate the bacteria without deleteriously affecting the desired properties in the tissues or oil extracted therefrom. The preferred alkalis are those which, in addition to producing the desired hydrogen ion concentration, are also cheap, non-toxic and harmless so that if accidentally spilled on the edible fish no harm will be done. In addition, the preferred alkaiis do not change the appearance of the viscera, particularly in the case of livers. Though various alkalis may be used, I have found that soda ash (crude sodium carbonate) or pearl ash (potassium carbonate) possesses the aforementioned properties and, therefore, is admirably suited for the purposes of this invention.

As illustrative examples of other alkalis capable of use in the instant invention may be mentioned alkali hydroxides, such as, for example, sodium hydroxide, potassium hydroxides; alkali salts, such as trisodium phosphate; and ammonia and substituted ammonia compounds, such as ammonium hydroxide, methyl amine, and ethyl amine.

The quantity of the alkali which is employed in accordance with the principles of this invention may vary. The precise minimum quantity can be determined by simple empirical tests. In the case of soda ash or pearl ash, I have found that a quantity constituting 4%.to 10% or higher of the alkali, based on the weight of the fish viscera. Optimum results 'are 5:. Wed when 5% soda ash or pearl ash,'based on the weight of the viscera, is employed.

In carrying out the process constituting another phase of the invention, strictly fresh viscera (livers, intestines, plioric caeca, etc), immediately after they are taken from the fish, are put in suitable containers, such as tight barrels, tin

cans, tubs or the like, and among them is sprinkled the dry selected alkali. Precautions and care should be taken to distribute the alkali well and uniformly throughout the viscera in the container. When the containers are filled, they may be closed and stored so that sunlight is excluded therefrom. Alternatively, the cans may be tightly closed.

Since the viscera are in the fresh condition, it is obvious that they are also in the raw or uncooked state.

Though it is not essential that viscera, preserved as herein described, be refrigerated by artificial means, it is always advantageous and desirable to keep them as cool as can be done, particularly if the process is practiced aboard fishing vessels.

From the foregoing, it is clear that the instant method is very simple and so easy to perform that it can be easily carried out at sea, even by unskilled persons under the rough conditions prevailing at sea.

When viscera is preserved as herein described, the product is suitable in every way for the extraction of vitamin-bearing oils of exceptionally high quality, light color, mild and agreeable odor and taste, and with the vitaminpotency fully retained. In addition to securing the results aforementioned. the viscera are preserved for extended periods of time and over a relatively wide range of temperature, such as, for example, 25 to C.

When livers are treated with the preservatives contemplated by this invention. and particularly soda ash, the product has all the appearances of 75 the raw fresh liver. There is no putrefaction, odor or disintegration of the cells.

Since it is obvious that various changes and modifications may be made in the above description without departing from the nature or spirit thereof, this invention is not restricted thereto except as set forth in the appended claims I claim:

1. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in -applying an alkali to said fresh viscera in an amount to produce such a high hydroxyl ion concentration as will inhibit the action of the enzymes of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

2. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in applying an alkali in dry form to said fresh viscera in an amount to produce such a high hydroxyl ion concentration as will inhibit the action of the enzymes of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the .oil extracted therefrom.

3. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in applying an alkali metal carbonate to said fresh viscera in an amount to produce such a high hydroxyl ion concentration as will inhibit the action of the enzymes of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

4. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in sprinkling a dry alkali metal carbonate on the fresh viscera to be preserved, the amount of said carbonate being such as to produce a hydroxyl ion concentration as will inhibit the action of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

5. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in applying an alkali to said fresh viscera in an amount from 4% to 10% based on the weight of the viscera, said alkali producing such a high hydroxyl ion concentration as will inhibit the action of the enzymes of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

6. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in applying an alkali metal carbonate to said fresh viscera in an amount from 4% to 10% based on the weight of the viscera, said carbonate producing such a high hydroxyl ion concentration as will inhibit the action of the' enzymes of the viscera tissue and the action of the bacteria which cause decomposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

7. A process of preserving fresh fish viscera containing vitamin-bearing oil which consists in' applying an alkali metal carbonate to said fresh viscera in an amount of 5% based on the weight of the viscera, said carbonate producing such a high hydroxyl ion concentration as will inhibit weight of the viscera, said carbonate producing carbonate being 5% based on the weight of the viscera, said carbonate producing such a high lrvdroxyl ion concentration as will inhibit the action of the enzymes of the viscera tissueand the action of thebacteria which cause deco mposition without deleteriously affecting the desired properties of the viscera tissue or the oil extracted therefrom.

10. A method of preserving fresh fish viscera containing vitamin-bearing oil which consists in increasing the hydroxyl ion concentration to a pH in excess of 9.0.

11. A method of preserving fresh fish viscera containing vitamin-bearing oil which consists in treating the fresh viscera with an alkali in an amount to increase the hydroxyl ion concentration to a pH in excess of 9.0 to inhibit the action of the enzymesand bacteria which cause decomposition without deleter'iously afiecting the desired properties in the viscera or the oil ex-- tracted therefrom.

12. A method of preserving fresh fish viscera containing vitamin-bearing oil which consists in treating the said fresh viscera with an alkali metal carbonate in an amount to increase the hydroxyl ion concentration to a pH in excess of 9.0 to inhibitthe action of the enzymes and bacteria which cause decomposition without deleteriously affecting the desired properties in the viscera or the oil extracted therefrom.

13. A method of preserving fresh fish viscera containing vitamin-bearing oil which consists in sprinkling the fresh viscera with an alkali metal carbonate in an amount to increase the hydroxyl ion concentration to a pH in excess of 9.0 to inhibit the action of the enzymes and bacteria which cause decomposition without deleteriously affecting the desired properties in the viscera or.

the oil extracted therefrom.

ROBERT H. BEDFORD. 

